The cliff itself is home to a wide range of breeding birds. By far the most numerous is the Common Guillemot or Murre with tens of thousands of pairs lining the ledges. It comes in two forms, an unadorned dark head and bridled form with white markings around the eye. The Razorbill is widely distributed about the Islands, never as numerous as the Common Guillemot.The Atlantic Puffin is found at Marwick Head but only in small numbers.The Black Legged Kittiwake has about 10,000 active nests at Marwick Head.The newly fledged young are distinctively marked, reminiscent of Sabine’s Gull.